JSFiddle - React, Tailwind, and code Playground

HTML

<nav>
        <ul>
            <li><a href="#">Link</a></li>
            <li><a href="#">Link</a></li>
            <li><a href="#">Link</a></li>
            <li><a href="#">Link</a></li>
        </ul>
    </nav><article>
        <h1>Inhalt</h1>
    </article>

CSS

html, 
body, 
nav, 
article {
    margin:0;
    padding:0;
    height:100%;
}
nav, 
article {
   display:inline-block;
   vertical-align:top;
}
nav {
    width:25%;
    background:#EEE;
}
article {
    width:75%;
    background:#AAA;
}